The work upon which this publication is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1964 and by the United States Department of Agriculture, Forest Service, Pacific Northwest Forest...
This research was designed to broaden the understanding of how timber-harvest affects aquatic macroinvertebrates in perennial and intermittent headwater streams. This study compared emergent and benthic macroinvertebrate assemblages from 20 headwater streams in the central Oregon Coast Range that varied by harvest condition and flow duration. Through comparison of the...
Riparian zone vegetation can influence terrestrial and aquatic food webs through variations in the amounts, timing, and nutritional content of leaf and other litter inputs. Differences in vegetation composition and density, as well as riparian topography, may modulate the strength and quality of these inputs. Changes in inputs to small...
Stream temperature, as an important component of stream ecosystems, can be affected by forest harvesting through removal of riparian shade and changes in hydrology. Riparian Management Areas
(RMAs), as implemented through the current Oregon Forest Practice Rules, are designed, in part, to maintain stream temperature following forest harvesting. However, effectiveness...
Riparian areas in the Pacific Northwest provide important biotic and abiotic
features, such as down wood, moist microsites, and abundant invertebrate prey that
benefit aquatic and terrestrial amphibians. Reported high densities of amphibians from
streams and riparian areas in the Pacific Northwest highlight their importance in riparian
food webs. Amphibians...
Tree species directly and indirectly affect soil nutrient cycles. I sought to characterize soils and foliage associated with four common canopy tree species (Douglas-fir, western hemlock, western redcedar, and bigleaf maple) in mixed-species old-growth forests of the Oregon Coast Range and to determine whether and how soils differ among the...
The Early Oligocene Oregon Coast Range Intrusions (OCRI) consist of gabbroic rocks and lesser alkalic intrusive bodies that were emplaced in marine sedimentary units and volcanic sequences within a Tertiary Cascadia forearc basin. The alkalic intrusions include nepheline syenite, camptonite, and alkaline basalt. The gabbros occur as dikes and differentiated...
Vegetation provides food for many insects, and many insects serve as food for bats. We investigated the linkages among these three trophic levels in riparian areas throughout the Oregon Coast Range by examining the influence of vegetation cover, composition, and structure on the activity of nocturnal insects and bats, the...
Western forests have become increasingly fragmented landscapes dominated by young stands. Given that western Oregon forests largely consist of headwater systems, there is a need to better understand how headwater forest taxa and their habitats are impacted by forest management practices. Several amphibian species associated with forested headwater systems have...
For nearly two decades, foresters in the Oregon Coast Range have been witnessing a substantial decease in Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco.) vigor and growth, caused by Swiss needle cast (Phaeocryptopus gaeumannii). Currently, no solutions are in sight but aerially-applied sulfur may alleviate Swiss needle cast and its...
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Temesgen Hailemariam
For nearly two decades, foresters in the OregonCoastRange have